Automatic focusing apparatus for photographic lenses.



L. J. R. HOLST. AUTOMATIC POCUSING APPARATUS FOR PHOTOGRAPHIG LENSES.

APPLICATION FILED MAY 8, 1911. 1,029,295, Patented June 11, 1912.

6 SHEETS-SHEET 1.

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OTOGRAPHIG LENSES.

L. J R. HOLST.

ABATUS FOR-PH 0N IILED MAY 8 USING A PP APPLIGATI A TTORNE Y mm 0 CW 9R5mrmxmxmxmtmxmxmxmlw l 4 VENTOR 6 SHEETS-SHEET 3.

Patented June 11, 1912.

L. J. R. HOLST. I AUTOMATIC POOUSING APPARATUS FOR PHOTOGRAPHIG LENSES.

xmlcymmxmxmxmxmrmlm APPLICATION FILED MAY 3, 1911.

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L. J. R. HOLST. AUTOMATIC FOGUSING APPARATUS FOR PHOTOGRAPHIG LENSES.APPLICATION FILED MAY 8, 1911.

1,029,295, Patented June 11,1912.

6 SHEETS-SHEET 4.

WITNESSES v 'BY UMMQQ. r ATTORNEY L. J. R. HOLST.

AUTOMATIC FOGUSING APPARATUS FOR PHOTOGRAPHIG LENSES.

APPLICATION FILED MAY 8, 1911. 1,029,295. Patented June 11, 1912.

6 SHEETSSHBET 5.

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L. J; R. HOLST.

AUTOMATIC FOCUSING APPARATUS FOR PHOTOGRAPHIG LENSES.

APPLICATION FILED MAY 8, 1911.

m 1 H T M A, n m u E J H d S IE 6 n .m a P Z M 7 I70 2 m lu lh v 6 w Ay? w nw 2 A 0, q 6 m 1 0 4m 5 5 M m UNITED sTATiis- PATENT OFFICE.

LODEWYK J. R. HOLST, 0F LANSDOWNE, PENNSYLVANIA, ASSIGNOR T0 WILLI LETS,

BROWN AND EABLE, INO OF PHILADELPHIA, PENNSYLVANIA, CORPORATION OFPENNSYLVANIA.

AUTOMATIC roousme APPARATUS non PHOTOGRAPHIC LENSES.

Specification of Letters Patent."

Patented June 11, 1912.

Application filed May 8, 1911. Serial No. 625,872.

nuse of the triangle, if swung about a point in itself at equaldistances from the rectangular sides of the triangle, intersects therectangular sides of such triangle at points, which not. only areadapted to positively establish such conjugate-foci, but also withcertainty maintain the true mathematical relation of the conjugate-focipreviously es-' tablished.

According to my invention it is to be understood'that focusing is therelative'adjustment of a lens with relationto 'anobject, and the imagethereof which such lens projects. v A A.

The principal object of my present invention is to provide means toestablish and or shiftings to various positions as r uired of a lens andof the support for the image to enable the image to hear an exactpredetermined ratio of'enlargenient or of reduction to the object.

It 1s a well known fact that in focusing in the customary manner it hasbeen possible in practice to obtain only approximately a predeterminedrelation of size hitherto restricted to a margin Within about two percent. of the real size required.

Some ofthe convenient forms of carrying out my invention which have beenfound practically efficient are shown in the accompanyingdrawingsforming part hereof, in

Figure It, represents a side elevational view, partly \111 brokensection of an apparatus as'employed with a type of camera in common usefor photo-mechanical work, embodying features of my present invention.Fig.af2, is'en elevational View in cross-secthe center of the fulcruinedguideswi tion on the line A, A, of Fig. 1, but drawn to a larger scalethan shown therein. Fig. 3, is a slde elevational view of a part of amodified form of the apparatus, in' which the vertical guide-armoccupies, as shown,

an upright position with respect to the camera-bed. Figs. 4 and 5, arerespectively plan views of the camera-bed of Fig. 1, showin modifiedmeans, whereby movement- 0 the focusing device may. be communicated inincreased proportions to the lens and plate holding frames of thecamera, em-

b'odying further features of my said invention. Fig.6 is a sideelevational view of the modified type of the device as shown in Fig. 3,showing additional means to operate the same through the entire rangethereof from maximum reduction to maizimum enlargement in employing thesame operatingshaft. Fig. 6, is an enlarged view in side elevation ofthe locking device adapted -to coiiperate'with the rocker-' arm of thefulcrum slide. Fig. 7, is a cross-sectional elevation on the line B B ofFig. 6,drawnto the: same scale andshowing means to sup port themechanism on the camera-bed and operative-connections between saidmechanism and the lens and plate supports.

In these drawings correspon'din parts in the various figures have beenindicated' by the same numerals. maintain the conjugate-foci inadjustments bar 6, and to a bracket 37, at the rear end.

of a [guide-bar 5'. The corner plate 11-, also carries a short pin 9, tosupport a sleeve 9, which can be adjusted toward and away from thecorner-plate 11,-bylock-nut. 9 Thesleeve 9, carries oscillatoryfuicrumed guides 10, inisuch a roanner that;,-wh-1j the sleeve isadjusted on its supporting 3 travelin a line bisecting the right formedbythe guide-bars 5 and .6, consequently the center of the oscillatoryascrumed guides 1O, will at all times be equidistant from the guide-bar5 and the guidebar 6. The guide-bar 5, carries a sleeve 7, and theguide-bar 6, carries a sleeve 8, both of which are adapted to slidealong these bars under the control of a pair of adjacent slide-rodsl and2. The sleeve 7, on the guide-bar 5, and the sleeve 8, on the guidebar6, are provided with lugs 7 and 8 respectively,through which holes aredrilled transversely to the direction of the said guide-bars, to serveas bearings for the pivot-pins i and 3 respectively, Fig. 2, clearlyshows the pivot-pin 4, which carries on its inner extremity the head ofthe sliderod 2, and supports in the cylindrical opening' of its outerpart the end of the slide-rod 1. Fig. 2, also shows the pivot-pin 3, inthe lug 8 of sleeve 8, on the guide-bar 6,

inserted in a direction opposite to that in' which the pivot pinis'placed in the sleeve 7, to serve as a pivot for the head-end of theslide-rod 1, and as a guide for the free end of the slide-rod'2. Theslide rods 1 and 2, pass also through the fulcrumed guides 10, asclearly shown in Figs. 1 and 2. The underside of the ide-bar 5, forms arack in the teeth of whlch engages a pinion 13, Fig. 2, mounted on aspindle 13 carried by suitable projections of the sleeve 7. The handwheel 12, aftords means for the rotation of the pinion 13, and therebymovement of the sleeve'7, along the said guide-bar 5.

The corner-plate 11, carries a sprocket 16, around which passes a chainor other suitable flexible band 16 toa similar sprocket 15, pivoted onthe bracket 35, at the foot of the guide-bar 6. Both ends of the chainor band 16*, are attachedto the sleeve 8, in a manner clearly shown inFig. 3. The sprocket 16, is rotated loy means of a crankhandle 14,carrying a pinion let, meshing with a spur-wheel 14:", mounted on thespindle of the sprocket- 16 behind said sprocket. The rotation of thehandle 14;, thus will cause the sleeve 8, to travel along the guidebar6. However, it should be understood that when the movable sleeves andsliderods are in the position shown in Figs. 1 and 2, movement can beimparted only by means of the hand-wheel 12, actuating the sleeve 7which on being impelled toward the corner-plate 11, will cause thesleeve 8, to slide in adownward direction on the guidebar 6, while anyattempt at moving the sleeve 8, by means of the crank-handheld,

will only result in straining the mechanism, but cannot give motion ineither direction to the sleeve 7. This condition prevails until thesleeves? and 8, and the slideods 1 and 2, have reached the centralposition oi their course, as shown a in Fig. 3. in case the sleeve 7,must be moved nearer to the cornor-plate 11, thanthe central position,the

motive power must be applied byfmeans oi? the hand-crank 14, to thesleeve 8, on the guide=-bar 6, which sleeve on being impelled away fromthe corner-plate 11, will cause a further approach of the sleeve 7,toward the said plate. In general, it will be seen that the motive powerfor the operation of the said mechanism must be ap lied to the sleevewhich travels between the central position and the outward limit of itsstroke and it is' immaterial whether it moves toward or away from thecentral posit-ion. This demonstrates that the point of application ofthe motive power changes when the parts reach the central position andare to be driven'fartherin the same direction. The carriage formed bythe corner-plate l1, and the guide bars 5 and 6, is held in properposition with regard to the bed of the camera by means of brackets26, alowerllateral clearlyshown in Figs. 1 and 2.

As illustrated in the drawings, the objectsupport 39 is immovable andthe difierent proportions between object and image are obtained byimparting movement to the lens and the image receiving surface. Thismakes it necessary to provide means whereby the carriage can movelongitudinally relative to the bed of the camera, as much as the sleeve8, moves vertically along the guide-bar 6. This longitudinal movement ismechanically obtained by means of the following devices or theirequivalents.

The corner-plate 11, carries a spindle 19, and the end-bracket 37carries a spindle 37 Fi s. 1 and 2,both projecting toward the camera-bed25.. On these spindles are 1 and 2, rolling on the upper edge or" thebar 38, as illustrated in Figs. 1 and2. At either end of the lateral bar38, are attached right-angle brackets 32 and 33. brackets support ontheir horizontal flanges, a flexible band 32,drawn taut and passing fromthe bracket 32, over the drum 17, on the corner-plate 11, over the drum34, on the bracket 35, then upward over the drum 18, on the corner-plate11, and then rearloosely mounted on the spindle 19, which carries thegrooved-pulley 19 This pulley has a diameter corresponding with that ofthe drum 18. The part of the flexible band situated between the drum 31, and the drum 18, is attached to a lug on the sleeve 8, so that anymovement of the sleeve along the guide-bar 6, will cause a correspondingmovement of the carriage formed by the corner plate 11 and partsattached thereto,

sleeve 8, moves downward it will cause. an equal amount of rearwardmovement of said carriage and when the sleeve 8, moves upward movementthereof. in this manner the bar 27 and an upper lateral bar 38, as

mounted grooved pulleys l9? and 37 Figs.v

ward to the bracket 33. The drum 18, is

ward it will cause an equal amount of for These along the supporting bar38. When the 'longitudinal displacement of the carriage be multiplied byfactors conveniently ob-.

tainable in gears, whereby one standard size of mechanism may be made tooperate lenses of any focal length met with in actual practice. To thisend, the sleeve 9, supported on the angular extension of thecorner-plate 11, is adjustable between limits permitting of the bringingof the center of the oscillatory fulcrumed guides 10, at any pointbetween say 6 and 7 inches distance from the lines of motion of thecenters of the pivots 3 and 4-. The exact distance of the center of theoscillatory fulcrumed guides 10, to the said centerlines of motion iscalled the master focus of said mechanism, which master focus whenmultiplied by the ratio of the gearing, must be equal to the equivalentfocus of the lens used.

By using gears of varying proportions of say, 1 to 2; l to 2. 1 to 3; 1to 8. 1 to 4; the aforesaid apparatus can be applied to lenses of anyfocal length from 12 to 28", and thus embrace practically all classes ofwork, in every-day practice. In Figs. 4 and 5, are illustrated two modesof comnuinicating such multiplied movement of the focusing mechanism tothe lens and int-age supporting frames, in plan.. Fig. 5, illustrates asuitable multiplication device for use in connection with the apparatusof the types illustrated in Figs. 3, 6 and 7. In Fig. 5, thecorner-plate 11, stands for the carriage of thefocusing mechanism andthe sleeve 7, represents the corresponding part of Figs. 3, 6 and 7. Achain or other suitable flexible band 53, is stretched from thecorner-plate 11, Fig. 5, over a sprocket 40, on the spindle 31, at rightangles to the camera-bed, and near the object surface 39, and passesthen rear 'ardly oven the sprocket 41, loosely mounted 011 the end ofthe spindle 29, and then forwardly to the end of the bracket- 37. Thespindle 31, also'car'ries keyed to it a sprocket 42, over which iscarried an endless chain 53, supported on a like size, but freelyrevolving, sprocket 43, on the spindle 29. The bottom board of the lenscarrying frame 23, is attached to the upper stretch of the chain 53 bymeans of the downwardly projecting lugs 23. The amount of movement ofthe corner-plate 11, will thus be transmitted to the lens supportingframe 23, in proportion to the diameters of the sprockets 4.0 and 42. Inlike manner the movement of the sleeve T, is transmitted to theplate-support 22. The inwardly projcct ing pivot of the oscillatoryguide attacl'ied to the sleeve 7, is the driving point of an endlesschain 52. which is stretched around the sprockets lG and =17 carriedrespectively. by the spindles 2t) and 36. The sprocket 17, is freelymounted on its spindle and the sprocket 4-6 is keyed to the spindle 2%).The large sprockets l8 and 18 are also keyed to the spindle 29, whereasthe similar sprockets at) and :19, rotate freely on the spindle 31.Endless chains and T5, are strctc ied around the sprockets +8, 49 and 1849 respectively, and will thus be driven through the same increaseddistances relative to the course of the pivot of the guide 1, as is thecase of the chain 53 relative to the course of the carriage 11, as allthe small and large sprockets bear the same relations to each other.Suitable clamps 22 and 22", pro jecting downwardly from theplate-carrier 22, attach the latter to the chains 75 and 75 and finallycommunicate the required movement to the image surface.

The mode of transmission illustrated in Fig. 4, is a mechanicalmodification of the means illustrated in Fig. 5, and is adapted for usein connection with a focusing mechanism of the type illustrated in Figs.1 and 2. The endless chain 7t, passes over the sprocket 30, keyed to thespindle 31 and thence rearward to the like size sprocket 30looselymounted on the spindle 29. Movement is communicated to the chain7%, through the action of the spur-gear 50", on the rack 50, as shown inFigs. 1 and t. The spurgear 50 is keyed to the spindle 15,), which alsocarries freely mounted on it the drum 18, and keyed to it the groovedpulley 19, and the pinion 18, which latter meshes with the stationaryrack 21. The amount of movement of the chain 74, is thus determined bythe proportion of the pitch diameters of the pinion 18, and thespur-gear 50.

In Fig. 2, is clearly illustrated the grooved pulley 37", the pinion21*, and the spur-gear ol all keyed to the spindle 37, carried in'downwardly projecting lugs of the sleeve 7. The pinion 21 of the samediameter as the pinion 18", meshes with the stationary rack and thespur-gear 51 is ofthesame di ameter as the spur-gear, 50 and meshes withthe rack- 51, which is inserted in the endless band formed by the chain73. This chain is stretched over the sprocket 28, loosely mounted on thespindle 31, and over the sprocket 28*, keyed to the spindle 29. Thespindles 29 and 31 carry at their oppo site ends similar sprockets 28 30and 28 30, respectively. Of these, the sprocket 30,

is keyed and the sprocket 28, is freely. mounted on the spindle 31, andthe sprocket 28, is keyed and the sprtcket 30 is freely mounted on thespindle 29. These sprockets serve to carry endless chains 73 and 7 Thesprocket 30, is keyed to the spindle 31, and the sprocket 28 is keyed tothe spindle 29, which arrangement results in the communication ofmovement to the chain 73*, equal to that of the chain 73, and thus toprovide means to fasten the lens supporting frame 23, to the chains 74and 74 and the image supporting frame 22 to the chains 73 and 7 3 tothereby finally transmit the movement of the corner-block 11, and sleeve7, respectively, to these parts in an increased ratio determined by therelation of the pinions 18 and 21 'to thespur-gears 50 and 51 In Fig. 3,is'illustrated a modification of the manner of adjusting the oscillatoryful-,

crumed guides 10 in the slot 9 by means of the set screws 9*, atdifferent distances from the rectangular guide-bars 5 and 6, and how thelatter can be placed in an upward position with relation to thecamera-bed, whenever desirable. It further illustrates how the motivepower for the sleeve 7, can be applied from a crank 12, fitted to thecorner-plate l1, and by means of an endless chain 12 instead of by therack and pinion, as shown in Figs. 1 and 2. In this type of constructionthe pivot pin 19, in the corner-block 11, carries besides the sprocket16, a pinion 21 meshing with the inverted stationary rack 21. Thisarrangement causes the carriage to travel longitudinally over thesupporting track 27, an equal distance as the sleeve 8, travelsvertically along the guide-bar 6. A groove in the upper face of the rack21, serves as a track for the guide-wheel 75, pivoted on a suitablebracket carried by the brace-rods 36, so as to maintain the device in avertical position.

In. Fig. 6, is ilustrated a further modification of how the sleeves 7and 8, may be automatically connected and disconnected with the drivingshaft runningparallel to the camera-bed and so arranged as to beconveniently operated by the photographer, while standing at his workbehind the ground glass. A shaft 61, is carried in brackets 64 and 65,attached to the cornerpiece 11. Between these brackets a worm 56, isslidably mounted on the shaft 61, and caused to rotate with it by meansof a key or other convenient means. The hub of the worm extends eitherway and ends in half clutches designed to engage in corresponding halves57 and 59, forming parts of the spiral-gears 57 and 59. The illustratedpositionof the said movable parts, shows their e1 position after thesleeve 7, has been ward to its central position. The y. fulcrumed slide10, is provided h lug 67, from which a pin 71, projectsi'transversely,andenga'ges in a slot of amazes bracket 53. This lever is slotted inorder to allow the required diagonal adjustment of the fulcrumed slides10, in the extension 9 of the corner-piece 11. The pin 71, causes thelever 52 to rock around its own pivot in harmony with the oscillatie efthe fulcrumed slide 10, and will reach its central position togetherwith the slide 10, Whatever may be its adjustment in the extension 9 Thelower extremity of the lever 52 is. in the form of an arc of a circlefrom its center point and notched in the middle, thereby allowing thepin- 66, at the end of the swinging arm 66 pivoted at 66, in the bracket53, as clearlyshown in Figs. 6 and 6 to be lifted by a suitable spring54", out of the recessed upper side of the connector 54, which itselfrests on a roller 72, mounted on the stud 72, carried by the bracket 53.The freeing of the connector 5 1, permits the worm-teeth of the lowerhalf of thelever to engage with the worm 56, which will then cause thelever 55, to oscillate, until the other recess of the connector 54,registers with the pin 66. The continued rotation of the shaft 61, willthen cause the worm 56, to slide out of engagement with the spiralgear59, which meshes with the spiral gear 60, operating the chain 12 andfinally to engage in the hub of the spiral-gear 57. In the meanwhileconti ued rocking of the fulcrumed slide 10, and ever 52*, will causethe pin 66, to embed itself in the opposite recess of the connector 54,which, by reason of its not being exactly opposite the pin 66, willcause, at the same time, a slight addi-, tional movement of the lever55, whereby the worm teeth of this lever will be brought just beyond thereach of the end of the worm 56. The driving power of the shaft 61, isnow transmitted to the sleeve 8 through the spiral gears 57 and 58, andthe chain 82, and will continue to move the said sleeve, until by therotation of the shaft 61, in a reverse direction, the sliding rods 1 andQ, are brought again into their central position. The distance betweenthe inner clutch surfaces 57 and 59 of the spiral gears 57 and 59,prevents the worm 56, to ever engage both simultaneously, so that theshaft 61, will rotate for a short period, without driving eitherslide-block. Fur: thermore the gear sets 57, 58 and. 59, 60, are soproportioned that anyone of the said wheels may be either a driver or adriven wheel. The movement of the plate and lens supporting frames isderived from the said sleeves 7 and 8, and by the same devices as areillustrated in Fig. 5, and 7. Fig. 7, also illustrates how by means ofthe bracket 62 and rollers 63, the mechanism is kept upright, Whiletraveling along the guide 38,

and over the support 27.

The manner of operating the focusing apparatus of either typehereinbefore .described is as follows :First, the focal length of thelens to be operated by the device is accurately measured and divided byany of the gear proportions indicated in the foregoing description,which will give a quotient between 6 and 7. For instance, if the focallength be 16.25 inches, we divide by 2% and get 6.5 as quotient. Thediame ters of, the pinio-ns and spur-wheels operating the tooth-racksdescribed in Figs. 1, 2 and 4, or the. sprocketsdescribed in Figs. 3, 5,6 and 7 operating the lens and plate driving chains, are regulated toagree with the proportion 1 to 24 next the distance of the center of theoscillatory fulcrumed block 10, is adjusted to be exactly 6% inches,from the linesthrough which the centers of the pivot-blocks 3 and 4,Figs. 1, 2, 3, 6 and 7, move; then the slide-rods 1 and 2, are

, brought to their central positionas shown in Fig. 3. With the focusingmechanism in such adjustment, the lens-support is placed at a point sothat the distance between the object and the firstnodal point of thelens is exactly 32.5 inches and in this position the lens-support isfirmly clamped to the upper stretch of the chain provided for drivingit. Next the image-support is moved to the position which brings theimage-plane at exactly 82.5 --inches behind the second nodal point, inwhich position, the said image-support is also firmly clamped to the.chains provided for driving the same. The.

equipment is now properly adjusted in all its parts to produce an imagen equal size to the object and any movement imparted by the operatingdevices described for each type of construction, will cause the lens andthe image surface to always move in proper relation to each other, tomaintain sharp images of various sizes dependent Jlpon t-he distancebetween the object and the lens and within the capacity or limits ofmagnification or reduction for which the device is designed.

It will be manifestly obvious to those skilled in the art to which thisinvention appertains, that still further modifications as to details inarrangement of the device may be made and still come within the spiritas well as scope of my said inven-' tion; and hence I wish it to beunderstood that I do not limit myself to all the detailed arrangementsof 'the'same, as shown; but

Having thus described the nature and objects of my invention, what Iclaim as new and desire to secure by Letters Patent, is 1. In anautomatic focusingapparatus for photographic lenses, a pair ofguide-ways arranged at right 'angles to each other, a sleeve movablealong each of said ways, two slide-rods engaging said s eeves, each ofsaid sleeves car ng the pivot for one slide-rod and a guide for theother slide-rod, and an oscillatory fulcrum-slide through which both ofsaid slide-rods are guided, substantially as and for the purposesdescribed.

2. In an automatic focusing apparatus for photographic lenses, a pair ofguide-ways arranged at right angles to each other, a sleeve movablealong each of said guidew-ays, two adjacent slide-rods engaging saidsleeves, said slide-rods respectively terminating in said sleeves, andan oscillatory fulcrumed slide through which both of said slide-rods areguided, substantially as and for the purposes described.

8. In an automatic focusing apparatus for photo aphic lenses, guide-waysarranged at rig t angles to each other, sleeves movable along saidguide-ways, two slide-rods respectively engaging with and terminating insaid sleeves, and a driving mechanism for said sleeves, substantially asand for the purposes described.

4. In an automatic focusingapparatus, a

at right angles to each other, sleeves movable along each of saidguide-ways, each of said sleeves carryin a pivot and a slide, rodsattached to said pi'vots and guided in said slides, driving-mechanismfor said sleeves, an oscillatory fulcrumed slide guiding said rods, 2.rocker-arm carried by said fulc'rumed slide, and operative connectionsbetween said rocker-arm and drivingmechanism to lockand unlock saidsleeves to and from said drivin -mechanism.

5. In an automatic focusing apparatus, a carria e, comprising guide-waysarranged at rig t angles to each other, a sleeve movable along each ofsaid guide-ways, a rod pivoted to each of said sleeves, a lenssupporting frame, operative connections to transmit the movement of oneof said sleeves .to said lens supporting frame, a frame carone of saidsliding blocks to said lens-supporting frame, a plate-supporting frame,and operative connections totransmit the movement of the other of saidslidingblocks in equal, increased, or decreased ratie, to saidimage-supporting frame, substantially as and or the urposes described 7.In an automatic ocusing apparatus for photographic lenses, sleeves,guide tracks forming a carriage, said sleeves carriage comprisingguide-ways arranged guided along said tracks at right angles to eachother, a sliding rod pivoted to each of said sleeves and slidahly guidedthrough the other of said sleeves, a lens-support and lens, meanswhereby said lens-support is operatively connected With one of saidsliding-rods, a stationary support for said guide tracks, and operativeconnections between one'ot said sleeves and the stationary support,whereby said guide tracks are caused to move longitudinally parallel tothe axis of the lens the .same distance as said last named sleeve movesin a path at right angles to the axis of said lens.

8; In an automatic focusing apparatus for photographic lenses, astationary support, sleeves, guide tracks forming a carriage, saidsleeves guided along said tracks at right angles to each other, twoadjacent sliderods engaging said sleeves, one of said sliderods pivotedto each of said sleeves and slidably guided through the other of saidsleeves, a driving-mechanism to move said sleeves along said guidetracks, a fulcrum'ed slide guiding both of said slide rod -operativeconnections between said 'i ulcrumed slide and driving-mechanism toengage and disengage said sleeves to and from'said driving-mechanism, alens, supports tor-saidlens and for. an image, and operativeconnections" between one of said sleeves and said stationary support,whereby said guide tracks are caused to move parallel to the axis ofsaid lens, through the same distance as said lastnarned sleeve moves atright angles to the axis of said lens.

9. ln a focusing apparatus for photographic lenses, an object-support, alenssupport, an image-support, means to estab lish and maintain theconiugate-r' oci in shiitings of said image support or lens support'toenable thereby the image to hear an exact predetermined ratio of enlargementor of reduction to the object, one element of said means terminatingin and moving along a path at an angle "to the ath of motion andtermination of another like element of said means, a fulcrum anyshittings of said image-support or lens {supportto enable thereby theimage to hear an exact predetermined ratio of enlarge mentor ofreduction to the object, one element of said means terminating-in andmoving through a path at right angles to the ncaaeoa path of motion andtermination of another like element of such means, a fulcrum slidehaving provision for both of said elements to slide through the same andoperative connections between the terminals of said like elementscausing said terminals to move in paths located at right angles to eachother.

11. In a focusing apparatus, an object support, a lens support, and animage support, a carriage comprising guide-ways arranged at right anglesto each other, and means movably connected With said guide- Ways,.oneelement of said means terminating in and moving through a path at rightangles to the path of motion and termination or the other element ofsaid means, a fulcrum-slide having provisions for both of said elementsto be guided through the same and operative connections lJQiBWEBIl saidmeans and said object-support, lens-support and image-support,respectively, substantially as and for the purposes described.

12. In a focusing apparatus for photographic lenses, an object-support,a lenssupport, an image-support, and means, one element of whichterminates in and moves through a path at right angles "to the path ofmotion and termination ofanother like element of such means, a fulcrumslide having provision for both of said elements to he guided throughthe same operative connections between the terminals of said likeelements causing said-terminals to move in paths located at right anglesto each other, and operative-connections to transmit in the same,increased, or decreased raticr, the movement of the'terminal of one ofsaid like elements 'to the lens-support, and in the same, increased, ordecreased ratio, the movement-of the terminal of the other like elementto said image-support, substantially as and for the purposes described.

13. in a focusing apparatus for photographic lenses, two tracks, tivosleeves guided by said tracks, two slide-rods, each of said slide-rodspivoted to one of said sleeves and slidahle through the other of saidsleeves, a lens-support, a plate-support, and means to impart themovement of said sleeves-respectively, to each cit said supports tocause the relativemovement of the latter to always equal in proportionthe relative movement-of said sleeves, substantially as and forthepurposes described.

In Witness whereof, I have hereunto set my signature iii-the presence ofthe two-subscribing Witnesses hereto.

, LGQEWYK J. HQLST.

/Vitnesses:

ELISABETH 2i. Snnnnaann, TnoruA-s SMITH.

